I have spent a working lifetime designing electronic system and it is *utterly beyond my comprehension* why dometic did not add a beeper to the LED "no gas" flashing mode - it could have been easily silenced by a simple button press.
If the gas runs out two minutes after I've gone to bed I would prefer to be woken by a beeper than have my fridge and freezer'c contents destroyed.
The answer to your question Dick0 is that it should be straightforward to add a beeper in parallel to the LED array. LEDs draw relatively high current and piezo beepers next to nothing so the electronics should handle it well.
Personally: I suggest we send someone round to dometic to beat up their fridge designer!
__________________
"I beseech you in the bowels of Christ think it possible you may be mistaken"
Oliver Cromwell, 3rd August 1650 - in a letter to the General Assembly of the Kirk of Scotland
I have a Dometic Elux RM2555 Type C40/110, three-way Refrigerator (late 2019 model) - It has an audible alarm; when it runs out of gas, power failure 12 & 240volt, or door left ajar. My previous van's (2014) Dometic refrigerator also had alarm.
Perhaps your refrigerator/s do have the feature but not wired correctly?
__________________
Possum; AKA:- Ali El-Aziz Mohamed Gundawiathan
Sent from my imperial66 typewriter using carrier pigeon, message sticks and smoke signals.
My Dometic fridge is the RM4605 and does not include audible alarm.
I have run out of gas a number of times during the night and it would be an advantage to know when gas supply has extinguished.
Knowing that would merely result in switching gas bottle supply rather than fridge beginning to warm after a number of hours.
I find not having an audible alarm a nuisance.
I have tried parallel connection to LED (correct polarity), however, when fridge is turned on the audible alarm activates (false alarm), for reason unknown to me.
So that was not the solution.
Perhaps someone has a fix?
__________________
Cheers, Richard (Dick0)
"Home is where the Den is parked, Designer Orchid Special towed by Jeep Grand Cherokee Limited"
"4x250W solar panels, Epever 80A charger and 3x135Ah Voltax Prismatic LiFePO4 Batteries".
A simple fridge thermometer from Jaycar has and inbuilt alarm.
Yes, I have one of those. But that would only go off hours later when the fridge/freezer temperature has already risen to an undesirable level.
My fridge does not even have LEDs, but a gauge down at floor level.
Perhaps a different solution would be some sort of pressure sensor in the gas line. Or, if the pilot light goes out, doesn't that activate a solenoid to cut off the gas? Tap into that circuit or attach another solenoid to that? You would need a switch to activate the alarm circuit only when needed.
-- Edited by Are We Lost on Thursday 22nd of December 2022 05:11:42 PM
As a long time casual user of 3 way refrigerators and on many occasions when it has run out of gas, it would be hardly noticeable loss of temp in a few hours during the night.
Beer drinkers might notice the warming of there beer but during the early hours they would not care, I feel sure.
When we are on the road travelling between an overnight camp and lunch we never run our refrigerator on 12 volt but the moment we stop it goes straight onto gas. 3 ways seem to have reasonable good insulation qualities holding it's temp for 3 to 4 hours. I did say reasonable insulation.
My portable 12 volt compressor in the ute is another story, we remember it was working at breakfast when I got some fruit juice out but at lunch time I thought the ginger beer was not as cold as I thought it should been 5 hours later, on checking it had a fuse holder failure.
Ps, our 3 way seem to like running out of gas after mid night, wife normally wakes me around 4 ish to let me know. No need for an extra audio alarm, her charming voice is enough.
Installed alarm for when gas goes out on three way fridge a. Buzzer -AB3462 $5.25 (Jaycar) b Thermal switch ST3821 (Jaycar) 60 oc Normally closed $6.50 c. Fuse holder 5 amp fuse SZ2015 $1.95 d. Switch to isolate
Mounted thermal switch on exhaust pipe of gas burner need to make bracket for good contact to the exhaust pipe
Takes 30 minutes for pipe to reach temp (buzzer off) Takes 20 min for buzzer alarm after gas off
Read this on a forum somewhere and I installed in 2015 so I cant take all the credit Laurie
-- Edited by laurieoz on Friday 23rd of December 2022 12:12:19 PM
-- Edited by laurieoz on Friday 23rd of December 2022 12:16:29 PM
Initially I thought, as you did Mike, that a simple fix should be a piezo buzzer in parallel with LED. Logical yes...LED comes on and buzzer is activated.
Well, the problem is there is a low voltage (millivolts) at the LED pc-board terminals. Which is why the larger buzzer, pictured, constantly buzzed when fridge was turned on and running on gas. It was just too sensitive to very low voltages.
As plan B, I had a spare buzzer for pc-board mounting, like those on computer motherboards, and a pic is attached of the fitted buzzer in parallel to the LED. It seems it is less sensitive than the original buzzer.
Turned fridge on, LED and buzzer activated (must be routine start up test) and when gas was selected as energy source the buzzer went quiet. I say quiet but it has a low volume and soft ticking pulsing sound similar to a quartz clock.
In any case, once the fridge control cover was replaced the ticking could not be heard...at least with my hearing.
With no gas flow the fridge goes into alarm mode, both LED and audible after 10 minutes. This time delay is built into the Dometic electronics.
The audible alarm is more than loud enough to wake me when asleep.
So a $4.00 buzzer connected in parallel and in correct polarity to the LED solved this problem.
Upon reflection I think I'll stay with the manual changeover. If I went auto I'm worried I would not notice the bottles had changed and, thus, run out of gas two weeks later = goodbye fridge/freezer contents.
Even though 3am changeovers are a pain I sleep badly nowadays so it doesn't really matter.
__________________
"I beseech you in the bowels of Christ think it possible you may be mistaken"
Oliver Cromwell, 3rd August 1650 - in a letter to the General Assembly of the Kirk of Scotland
I have spent a working lifetime designing electronic system and it is *utterly beyond my comprehension* why dometic did not add a beeper to the LED "no gas" flashing mode - it could have been easily silenced by a simple button press.
If the gas runs out two minutes after I've gone to bed I would prefer to be woken by a beeper than have my fridge and freezer'c contents destroyed.
The answer to your question Dick0 is that it should be straightforward to add a beeper in parallel to the LED array. LEDs draw relatively high current and piezo beepers next to nothing so the electronics should handle it well.
Personally: I suggest we send someone round to dometic to beat up their fridge designer!
Hi Mike,
I was having a think about a simple temp warning device and I remembered I used to use one of these controllers to maintain a set fermentation temperature for brewing beer. I also used one on a freezer to give me the option to either lager beer for an extended time or use the freezer to actually serve beer from a keg by running it at 3 deg c.
Anyway the controller could just easily be connected to a buzzer or light to indicate if the temperature of the fridge rose above normal operating temperature.
They are available in 12 v but I used to use the 240 v model to control the fridge temp. 12 v would be easy in a caravan if only used for a buzzer.
